1. Field of the Invention
The present invention relates to a guide system for tracing a present position of a vehicle to guide sight-seeing in the vicinity of a road being followed by the vehicle.
2. Related Art
There have been proposed a variety of navigation systems which are able to select an optimum route and guide travel to a destination by designating a starting point (or present point) and a destination. In the navigation systems proposed in the prior art, the course guidance is carried out exclusively by instructing rightward or leftward turns and/or the direction of advance with respect to intersections or landmarks.
In Japanese Patent Laid-Open No. 290473/1986, Japanese Patent Publication No. 19005/1988 and Japanese Patent Laid-Open No. 1520/1992, for example, there are proposed systems, in which storage means is provided for storing the sight-seeing information and in which the present position of the vehicle is detected and displayed on a map display, together with indication of the running direction, while the sight-seeing information is additionally output in voice.
In the guide systems of the prior art described above, however, a search may be conducted outward from the detected present position to locate an object of sight-seeing interest which exists near the present position or on the road ahead. However, with such systems it is impossible to provide guidance for objects other than those which face the road. It is also impossible to provide guidance for objects which are present near the road being or to be followed. Especially, an interesting and important "guidance object" (i.e., object to be covered by output of guidance information) not facing the road cannot be treated, even if present in the neighborhood of the present position or road ahead, because it cannot satisfy the conditions for guidance.